Poly(N-acetyl-D-glucosamine) is a known polymer which is a component of naturally occurring chitin. It is regarded as insoluble in conventional solvents, and, therefore, has been used as a powder. There is a demand for absorbable surgical elements, particularly sutures, which are strong enough of serve as a tissue retaining element during a healing process, and which then are absorbed by the living tissue. Requirements for the duration of useful strength vary widely with both the type of tissue and the surgical procedure. Some cosmetic purposes require strength for only a few hours or a few days. Other uses require strength for periods of months or even years. Advantageously, the surgical element should absorb promptly after it has served its useful function. Sutures have long been treated with dyes and therapeutic agents, poly(N-acetyl-D-glucosamine) sutures may be so treated.
Absorbable surgical elements usually start losing strength almost as soon as implanted, but a useful degree of strength is maintained for a much longer period. Complete absorption is, of course, much slower. Sharp changes in strength with time are not to be expected.